Final answer:
The most common measure of skeletal muscle mass is lean body mass. It provides a more accurate assessment of muscle mass compared to total body water, basal metabolic rate (BMR), or body mass index (BMI), which do not differentiate between muscle and fat mass.
Step-by-step explanation:
The most common measure of skeletal muscle mass is lean body mass. This term encompasses all of a person's body mass that is not composed of fat. Instead, it includes muscles, bones, organs, and other non-fat tissues. In comparison to other options, such as total body water, basal metabolic rate (BMR), and body mass index (BMI), lean body mass is more directly indicative of muscle mass. While total body water is related to muscle mass, it is not a direct measure. BMR is influenced by muscle mass because muscle tissue burns more calories than fat, but it is not a measure of muscle mass. BMI, on the other hand, calculates body size based on height and weight but does not differentiate between muscle and fat mass.
Men typically have a greater percentage of skeletal muscle mass and, therefore, a higher BMR when compared to women. However, lean body mass is a more specific measure for assessing muscle mass, as it reflects the weight of muscles without the fat. It is important to note that BMI has limitations especially in muscular individuals and may not accurately reflect body composition.